HLA class II induction in human islet cells by interferon-gamma plus tumour necrosis factor or lymphotoxin

HLA class II molecules are surface glycoproteins which are essential in the initiation of immune responses. It has been postulated that induction of class II in epithelial cells such as endocrine cells, which are normally class II negative, may result in autoimmunity. In type I diabetes, islet beta cells, the target of the autoimmune process, selectively express class II antigens. But in contrast to most other cell types, islet beta cells are not stimulated to express class II by interferon-gamma (IFN-gamma) and thus the conditions under which this induction occurs have been particularly elusive. The cytotoxins tumour necrosis factor (TNF) and lymphotoxin (LT) synergize with IFN-gamma in a number of activities. We report here that IFN-gamma in combination with either TNF or LT induces islet cell class II expression. This finding has important implications for the pathogenesis of type I diabetes and the understanding of the differential control of class II expression.

n-3 Polyunsaturated fatty acid (PUFA) deficiency elevates and n-3 PUFA enrichment reduces brain 2-arachidonoylglycerol level in mice

2-arachidonoylglycerol (2-AG) is a putative endogenous ligand for cannabinoid receptors and was suggested to play an important role in both physiological and pathological events in the central nervous system (CNS) as well as in peripheral organs. The sequential hydrolysis of arachidonic acid (20:4n-6, AA)-containing phospholipids has been proposed as a major biosynthetic route of 2-AG. On the other hand, the manipulation of the dietary n-3 polyunsaturated fatty acid (PUFA) status changes the AA level in tissue phospholipids. We, therefore, conducted two separate experiments to confirm whether the dietary n-3 PUFA status influences the 2-AG level in the mouse brain. In the first experiment, we fed mice with n-3 PUFA-deficient diet, which resulted in a marked decrease in the docosahexaenoic acid (22:6n-3, DHA) levels without a change in the AA level in brain phospholipids as compared with the mice fed with an n-3 PUFA-sufficient diet. The brain 2-AG level in the n-3 PUFA-deficient group was significantly higher than in the n-3 PUFA sufficient group. In the second experiment, we found that short-term supplementation of DHA-rich fish oil reduced brain 2-AG level as compared with the supplementation with low n-3 PUFA. The decrease in the AA level and the increase in the DHA level in the major phospholipids occurred in the brains of the mice fed the fish oil diet compared with those fed the low n-3 PUFA diet. Our results indicate that the n-3 PUFA deficiency elevates and n-3 PUFA enrichment reduces the brain 2-AG level in mice, suggesting that physiological and pathological events mediated by 2-AG through cannabinoid receptor in the CNS could be modified by the manipulation of the dietary n-3 PUFA status.

Current diagnosis and management of post-transjugular intrahepatic portosystemic shunt refractory hepatic encephalopathy

Transjugular intrahepatic portosystemic shunt has evolved into an important option for management of complications of portal hypertension. The use of polytetrafluoroethylene covered stents enhances shunt patency. Hepatic encephalopathy (HE) remains a significant problem after TIPS placement. The approach to management of patients with refractory hepatic encephalopathy typically requires collaboration between different specialties. Patient selection for TIPS requires careful evaluation of risk factors for HE. TIPS procedure-related technical factors like stent size, attention to portosystemic pressure gradient reduction and use of adjunctive variceal embolization maybe important. Conservative medical therapy in combination with endovascular therapies often results in resolution or substantial reduction of symptoms. Liver transplantation is, however, the ultimate treatment.

Long-term oncologic outcomes following radiofrequency ablation with real-time temperature monitoring for T1a renal cell cancer

OBJECTIVE

Few studies report long-term follow-up of renal cancer treated by radiofrequency ablation (RFA), thus limiting the comparison of this modality to well-established long-term follow-up series of surgically resected renal masses. Herein, we report long-term oncologic outcomes of renal cancer treated with RFA in a single institution.

METHODS AND MATERIALS

We retrospectively reviewed patients treated between November 2001 and October 2012 with laparoscopic-guided or computed tomography-guided RFA. All treatments were performed with real-time thermometry ensuring target ablation temperature (>60°C) was adequately reached. Only patients with biopsy-confirmed T1a-category cancer and a follow-up period>48 months were included in our analysis. Follow-up included office visits, laboratory work, and periodic contrast-enhanced imaging. Survival was calculated using the Kaplan-Meier analysis. Overall complications were reported using the Clavien-Dindo scale.

RESULTS

Of 434 RFA cases, 53 treatments in 50 patients met the inclusion criteria. Of these, 29 were treated with computed tomography-guided RFA and 24 with laparoscopic-guided RFA. The mean follow-up interval was 65.6 months (48.5-120.2), and the mean renal mass size was 2.3 cm (0.3-4.0). There were 4 (7.5%) local recurrences and 1 case of distant metastases with no local recurrence. The 5-year overall survival was 98%, cancer-specific survival was 100%, and recurrence-free survival was 92.5%. The complication rate was 26.4%, which included 71% of Clavien-Dindo grade I and 29% of grade II. Mean estimated glomerular filtration rate preoperatively and at the most recent follow-up visit was 77 and 66 ml/min, respectively.

CONCLUSIONS

When performed on selected patients, while monitoring real-time temperatures to ensure adequate treatment end points, RFA offers favorable long-term oncologic outcomes approaching those reported for partial nephrectomy.

Endovascular Management of Refractory Hepatic Encephalopathy Complication of Transjugular Intrahepatic Portosystemic Shunt (TIPS): Comprehensive Review and Clinical Practice Algorithm

Transjugular intrahepatic portosystemic shunt (TIPS) has evolved as an effective intervention for treatment of complications of portal hypertension. The use of polytetrafluoroethylene-covered stents have improved the patency of the shunts and diminished the incidence of TIPS dysfunction. However, TIPS-related refractory hepatic encephalopathy (rHE) poses a significant challenge. Approximately 3-7 % of patients with TIPS develop rHE. Refractory hepatic encephalopathy is defined as a recurrent or persistent encephalopathy despite appropriate medical treatment. Hepatic encephalopathy can be an extremely debilitating complication that profoundly affects quality of life. The approach to management of patients with rHE is complex and typically requires collaboration between different specialties. Liver transplantation is the ultimate treatment for rHE; however, the ongoing shortage of organ donation markedly limits this treatment option. Alternative therapies such as shunt occlusion or reduction can control symptoms and serve as a 'bridge' therapy to liver transplantation. Therefore, interventional radiologists play a key role in the management of these patients by offering a variety of endovascular techniques. The purpose of this review is to highlight some of these endovascular techniques and to develop a therapeutic algorithm that can be applied in clinical practice for the management of rHE.

Cytotoxic effect of IFN-gamma plus TNF-alpha on human islet cells

We have previously reported that the combination of IFN-gamma plus TNF-alpha is able to induce the de novo expression of HLA class II on human beta cells. In the present study, we have investigated the effect of these cytokines, alone or in combination, on the function and viability of human islet cells in vitro. Three hour insulin release was markedly reduced in human islet monolayer cultures after 4 days' exposure to 1000 U/ml of the combination TNF-alpha plus IFN-gamma (36.7 +/- 7.7, % of the control +/- SEM) or to TNF-alpha alone (49.5 +/- 7% of the control) while IFN-gamma had little effect. On direct inspection cell damage was clearly detected only in the cultures treated with TNF-alpha plus IFN-gamma in which staining by indirect immunofluorescence (IFL) for insulin revealed that the number of beta cells was also significantly reduced, thus suggesting a real cytotoxic effect of this cytokine combination. This effect was not beta cell specific since glucagon release and the number of alpha cells were also reduced in the cultures exposed to IFN-gamma plus TNF-alpha. 51Cr release experiments supported the cytoxicity of these cytokines to normal islet cells. There was a time course relationship between class II induction (2 days) and the cytotoxic effect of IFN-gamma plus TNF-alpha (4 days) on the same islet cells. In conclusion, these results indicate that the combination of IFN-gamma and TNF-alpha exerts a cytotoxic effect on human islet cells in vitro.

The utility of dobutamine echocardiography in preoperative evaluation for elective aortic surgery

BACKGROUND

Preoperative cardiac evaluations have been advocated prior to major vascular procedures to reduce the incidence of postoperative cardiac complications. This study was undertaken to evaluate the efficacy and predictive value of routine dobutamine echocardiography (DE) in the screening of patients undergoing elective aortic surgery.

METHODS

Dobutamine echocardiography was performed preoperatively on all patients having elective aortic procedures by our university surgical group from June 1995 to August 1996. The cardiac morbidity and mortality from this group were compared with that of a similar group undergoing elective aortic procedures from June 1993 to May 1995 with no dobutamine echocardiography (NDE).

RESULTS

Although there was no statistically significant difference in either overall mortality (4.4% in NDE vs. 2.3% in DE) or cardiac mortality (2.9% in NDE vs. 0% in DE) between the two groups, cardiac events occurred only in those patients with previous coronary artery disease. In addition, dobutamine echocardiography had a negative predictive value of 97%

CONCLUSIONS

Although routine screening is not necessary, selective screening of patients using dobutamine stress echocardiography is justified because of its high negative predictive value.

Cyclic GMP in the retinas of normal mice and those heterozygous for early-onset photoreceptor dystrophy

Cyclic GMP metabolism has been investigated in the retinas of mice that are heterozygous for a 'photoreceptor dystrophy' gene and have a lowered concentration of cGMP in their photoreceptor cells. The concentration of rhodopsin, retinal morphology and guanylate cyclase kinetics were normal. Cyclic GMP phosphodiesterase had a lowered affinity for cGMP. In accord with previous observations, chelation of exogenous calcium had no effect on cGMP levels in light-adapted retinas but increased them in dark-adapted tissue. The difference between cGMP concentrations in heterozygous and normal retinas in the dark was then eliminated. It was concluded that a modulator of cGMP phosphodiesterase activity is most likely to be causing the lowered steady-state level of cGMP in heterozygous retinas and that calcium is not involved.

Rates and determinants of HIV-attributable mortality among rural female sex workers in Northern Karnataka, India

Female sex workers (FSWs) have among the highest rates of HIV infection in India. However, little is known about their HIV-specific mortality rates. In total, 1561 FSWs participated in a cohort study in Karnataka. Outcome data (mortality) were available on 1559 women after 15 months of follow-up. To gather details on deaths, verbal autopsy (VA) questionnaires were administered to key informants. Two physicians reviewed the VA reports and assigned underlying causes of death. Forty-seven deaths were reported during the follow-up (overall mortality rate was 2.44 per 100 person-years), with VA data available on 45 women. Thirty-five (75.6%) of these women were known to be HIV-positive, but only 42.5% were on antiretroviral therapy (ART). Forty deaths were assessed to be HIV-related, for an HIV-attributable mortality rate of 2.11 deaths per 100 person-years. Absence of a current regular partner (incidence rate ratio: 2.79; 95% confidence interval [CI]: 1.39-5.60) and older age (1.06; 1.01-1.11) were associated with increased HIV-attributable mortality. Reported duration in sex work was not related to HIV-attributable mortality. We found a high HIV-related mortality rate among this cohort of FSWs; nearly 10 times that of national mortality rates among women of a similar age group. Older age, but not reported duration in sex work, was associated with increased mortality, and suggests HIV acquisition prior to self-reported initiation into sex work. Despite significant efforts, there remain considerable gaps in HIV prevention near or before entry into sex work, as well as access and uptake of HIV treatment among FSWs.

Secretory autoantibodies in primary biliary cirrhosis (PBC)

It is unclear how breakdown in immune tolerance to the ubiquitous self-antigen pyruvate dehydrogenase complex (PDC), seen in the autoimmune liver disease PBC, gives rise to tissue damage with such a limited distribution (restricted to the liver and salivary and lachrymal glands). One property shared by these tissues is the ability to export secretory IgA by the process of transcytosis. The aim of this study was to address whether active transcytosis of anti-PDC IgA occurs across epithelial surfaces in PBC, a finding that might implicate mucosal specific immune mechanisms in the pathogenesis of this disease. Parotid saliva was collected from PBC patients (n = 44), normal controls (n = 28) and PBC patients post-liver transplantation (n = 11). IgA and secretory component-positive antibodies specific for human PDC were quantified by ELISA and immunoblotting. PBC patients (but not control subjects) had anti-PDC IgA in their saliva. The strong correlation seen between titres detected using anti-IgA and anti-secretory component antibodies suggests that this is predominantly secretory IgA reaching the saliva by the active process of epithelial transcytosis. Titres of anti-PDC IgA remain high in PBC patients saliva post-liver transplant. Findings from studies of IgA in viral infection models raise the possibility that anti-PDC IgA could, whilst undergoing transcytosis, bind to newly translated PDC components in the cytoplasm of the epithelial cells transporting them out of the cell and inducing metabolic damage. This model would, if correct, help to explain the mechanism and tropism of tissue damage in PBC and the aberrant pattern of expression of PDC on the apical surface of biliary and salivary epithelial cells reported in this disease.

Suppression of platelet-activating factor generation and modulation of arachidonate metabolism by dietary enrichment with (n-9) eicosatrienoic acid or docosahexaenoic acid in mouse peritoneal cells

Several studies have shown that dietary n-3 polyunsaturated fatty acids (PUFAs) suppress platelet-activating factor (PAF) generation in leukocytes of humans and rodents, which is associated with the antagonism of arachidonic acid metabolism. Dietary eicosatrienoic acid (20:3n-9, ETrA) is also suggested to antagonize arachidonic acid (AA) metabolism, but its effect on PAF generation in leukocytes has not been defined. In the present study, we investigated the effects of an ETrA-rich diet on PAF generation and AA metabolism in mouse peritoneal cells, which were compared with those of a docosahexaenoic acid (DHA)-rich diet. Mice were fed a diet supplemented with a lipid preparation rich in ETrA, a DHA-rich fish oil (FO) or palm oil (PO) for 3 weeks, and peritoneal cells containing more than 80% of monocytes/macrophages were obtained. The peritoneal cells in the DHA and ETrA diet groups generated upon zymosan stimulation a smaller amount of PAF than cells in the PO diet group. In the peritoneal cells of the DHA diet group, AA contents in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were significantly lower than those in cells of the PO diet group, but those in phosphatidylinositol (PI) were not significantly different between the two dietary groups. A considerable amount of ETrA was incorporated into the peritoneal cells of the ETrA diet group, and AA was reduced as compared with the PO diet group. These changes occurred preferentially in PI but to a less extent in PC and PE. The amount of free AA released by the peritoneal cells upon zymosan stimulation was significantly reduced in the DHA diet group as compared with that in the PO diet group, whereas AA release was similar between the PO and ETrA diet groups. In conclusion, the effects of dietary ETrA on AA content in the phospholipid subclasses and AA release were quite different from those of dietary DHA, although both diets suppressed PAF generation in mouse peritoneal cells to a similar extent.

Irritable bowel syndrome in patients discharged from surgical wards with non-specific abdominal pain

A questionnaire was used to discover the prevalence of seven recognized symptoms of irritable bowel syndrome (IBS) in 96 patients who had been discharged from hospital 1-2 years previously with the diagnosis of non-specific abdominal pain. Compared with 1897 controls from a population survey in the same city, the patients were more likely to have these symptoms; the differences were statistically significant in most cases. The frequency of recurrent abdominal pain with features suggesting an intestinal origin was increased fivefold in male and fourfold in female patients (P < 0.001). Criteria for the diagnosis of IBS were present in 37 per cent of women and 19 per cent of men, versus 5 and 2 per cent respectively in controls (P < 0.001). Approximately half the patients remembered having symptoms of IBS at the time of admission and 70 per cent had had other attacks of abdominal pain. At the time of admission, the hospital notes mentioned the possibility of IBS in only 6 per cent of cases. Most patients would have welcomed an explanation for the pain at the time of their hospital admission.

An investigation into denture loss in hospitals in Kent, Surrey and Sussex

Background The loss of dentures for inpatients can have a detrimental effect on their well-being. Self-respect and dignity become compromised along with their ability to eat meals and communicate clearly, and long-term recovery.Aim This investigation aimed to identify the reported number of dentures lost in hospitals and the financial reimbursements given by trusts to replace them.Method Information on reported denture loss and reimbursement was collected in 12 trusts throughout Kent, Surrey and Sussex.Results Eleven out of 12 trusts returned data about how many dentures were lost in their hospitals, between them 695 dentures were reported lost over five years (2011-16). Seven trusts reported financial reimbursements for dentures losses; results showed £357,672 was reimbursed over six years (2010-16), the highest amount reimbursed for a single denture was £2,200.Conclusion The results indicate that denture loss is a problem in hospitals that contributes to the financial burden for the NHS. Consideration needs to be given by hospitals to find ways to reduce the number of dentures lost every year.

Ultrasound-Assisted Catheter-Directed Thrombolysis for Submassive Pulmonary Embolism

PURPOSE

Catheter-directed thrombolysis (CDT) is a relatively new therapy for pulmonary embolism that achieves the superior clot resolution compared to systemic thrombolysis while avoiding the high bleeding risk intrinsically associated with that therapy. In order to examine the efficacy and safety of CDT, we conducted a retrospective cohort study of patients undergoing ultrasound-assisted CDT at our institution.

METHODS

The charts of 30 consecutive patients who underwent CDT as a treatment of pulmonary embolism at our institution were reviewed. Risk factors for bleeding during thrombolysis were noted. Indicators of the right heart strain on computed tomography and echocardiogram, as well as the degree of pulmonary vascular obstruction, were recorded before and after CDT. Thirty-day mortality and occurrence of bleeding events were recorded.

RESULTS

Nine (30%) patients had 3 or more minor contraindications to thrombolysis and 14 (47%) had major surgery in the month prior to CDT. Right ventricular systolic pressure and vascular obstruction decreased significantly after CDT. There was a significant decrease in the proportion of patients with right ventricular dilation or hypokinesis. Decrease in pulmonary vascular obstruction was associated with nadir of fibrinogen level. No patients experienced major or moderate bleeding attributed to CDT.

CONCLUSION

Catheter-directed thrombolysis is an effective therapy in rapidly alleviating the right heart strain that is associated with increased mortality and long-term morbidity in patients with pulmonary embolism with minimal bleeding risk. Catheter-directed thrombolysis is a safe alternative to systemic thrombolysis in patients with risk factors for bleeding such as prior surgery. Future studies should examine the safety of CDT in patients with contraindications to systemic thrombolysis.

Early diagnosis of skin cancer based on segmentation and measurement of vascularization and pigmentation in Nevoscope images

This work presents techniques developed for automated image segmentation and classification of skin lesions as malignant or benign based on the ground truth. For each skin lesion two images are obtained, one in each of two different modalities of epiluminescence microscopy (ELM): side-transillumination which highlights the subsurface vasculature and surface pigmentation, and cross polarization, which only highlights the details of skin surface pigmentation. The automated procedure consists of three steps: i) Segmentation of images, using three segmentation methods; ii) Selection of the most accurate segmentation results based on a weighted scoring technique; and iii) classification of the lesion as malignant or benign by verifying the presence of a ring of hypervascularity around the lesion in the side transillumination images. The segmentation results were validated against manual segmentation by an expert and the malignancy results were validated against the result from pathology.

HLA DR, DP, DQ induction in human islet beta cells by the cytokine combination IFN-gamma + TNF-alpha

Human islet beta cells do not express HLA Class II normally, yet, in the diabetic pancreas, beta cells are selectively positive for Class II and this may facilitate their recognition by T cells. It has been demonstrated that human beta cells can be induced to express Class II when cultured with IFN-gamma + TNF-alpha or IFN-gamma + TNF-beta. To assess whether or not they can be induced to express the products of the Class II subregions, DR, DP and DQ, human islet cultures from 10 pancreas were supplemented with the combination of IFN-gamma + TNF-alpha using MoAbs specific for DR, DP and DQ products, and antibodies to insulin and glucagon. The combination IFN-gamma + TNF-alpha (100-1000 U/ml each) was able to induce the expression of the three subregions in both beta and alpha cells. The induction of subregion expression followed the hierarchy DR greater than DQ greater than or equal to DP. The capability of beta cells to express all three Class II subregions supports the possibility that these cells can present their self antigens to T cells.

Acute tumor lysis syndrome after proximal splenic artery embolization

Preoperative splenic artery embolization for massive splenomegaly has been shown to reduce intraoperative hemorrhage during splenectomy. We describe a case of tumor lysis syndrome after proximal splenic artery embolization in a patient with advanced mantle cell lymphoma and splenic involvement. The patient presented initially with hyperkalemia two days after embolization that worsened during splenectomy. He was stabilized, but developed laboratory tumor lysis syndrome with renal failure and expired. High clinical suspicion of tumor lysis syndrome in this setting is advised. Treatment must be started early to avoid serious renal injury and death. Lastly, same day splenectomy and embolization should be considered to decrease the likelihood of developing tumor lysis syndrome.

Mycotic aneurysm of the ulnar artery

A mycotic aneurysm is an uncommon, but serious, complication of infective endocarditis, occurring as a result of an infected embolus being lodged in the vasa vasorum or lumen of an artery. Involvement of the ulnar artery is rare, but its peripheral location renders its diagnosis more simple. A case of mycotic aneurysm of the ulnar artery complicating infective endocarditis is reported, with successful management by ligation and excision.

Measurements of benzo(a)pyrene in the city of Bombay for the evaluation of carcinogenic risk

Cigarette smoking, environmental chemicals and ionizing radiations are the three factors known to cause cancer in human beings. The relative importance of each of these is being constantly evaluated. There is an urgent need to monitor the environmental carcinogens on a large scale to assess the role of environmental chemicals in the incidence of cancer in human populations. Polycyclic aromatic hydrocarbons (PAH) are released into the atmosphere as a result of fossil fuel combustion and some of the PAH (e.g. benzo(a)pyrene) are recognised carcinogens. Measurement of benzo(a)pyrene in urban, suburban and rural regions of Bombay is carried out in order to evaluate the possible correlation with lung cancer incidence among different population groups. The variations in the concentration at the three sampling locations are discussed. The wide differences in the concentration at different locations seem to be very suitable for epidemiological investigations.

Transsplenic portal vein reconstruction-transjugular intrahepatic portosystemic shunt in a patient with portal and splenic vein thrombosis

Portal vein thrombosis (PVT) is a potential complication of cirrhosis and can worsen outcomes after liver transplant (LT). Portal vein reconstruction-transjugular intrahepatic portosystemic shunt (PVR-TIPS) can restore flow through the portal vein (PV) and facilitate LT by avoiding complex vascular conduits. We present a case of transsplenic PVR-TIPS in the setting of complete PVT and splenic vein (SV) thrombosis. The patient had a 3-year history of PVT complicated by abdominal pain, ascites, and paraesophageal varices. A SV tributary provided access to the main SV and was punctured percutaneously under ultrasound scan guidance. PV access, PV and SV venoplasty, and TIPS placement were successfully performed without complex techniques. The patient underwent LT with successful end-to-end anastomosis of the PVs. Our case suggests transsplenic PVR-TIPS to be a safe and effective alternative to conventional PVR-TIPS in patients with PVT and SV thrombosis.